import random
with open("Mac","r+") as fp:
 for i in range(100):
   hex_random="".join([random.choice("0123456789ABCDEF")for i in range(7)])
   fp.write(f"01-AF-3B-{hex_random[0:2]}-{hex_random[3:5]}-{hex_random[5:7]}\n")